| 摘要 |
<p>The present document relates to a current sensing circuit. In particular, the present document relates to a current sensing circuit which provides reliable indications of the current through a transistor. A current sensing circuit (220) configured to provide an indication of a load current through a pass device (21) is described. The current sensing circuit (220) comprises a sensing replica (22) of the pass device (21) and a sensing resistor (23) arranged in series with the sensing replica (22). The sensing resistor (23) is arranged such that a voltage drop at the sensing resistor (23) provides an indication of the load current through the pass device (21). The voltage drop at the sensing resistor (23) is dependent on an on-resistance of the pass device (21). Furthermore, the current sensing circuit (220) comprises a transformation circuit (25, 26, 227, 228, 29) configured to transform the voltage drop at the sensing resistor (23) into an output current, such that the output current is indicative of the voltage drop at the sensing resistor (23) divided by a compensation resistance of a compensation circuit (227). The compensation resistance exhibits a dependency on the on-resistance of the pass device (21) which corresponds to the dependency on the on-resistance of the pass device (21) of the voltage drop at the sensing resistor (23).</p> |
